In recent years, conventional cheese processing has been mechanized to improve the performance and efficiency of cheese manufacture. Several cheese making systems have been introduced for the continuous processing of raw cheese curd, including the draining of the whey from the raw cheese curd and the fusing, matting and subsequent miling of the cheese curd.
U.S. Pat. Nos. 3,636,630 and 4,217,818 describe continuous systems for the manufacture of cheese in which the curds and whey are separated either just before or on the first to two conveyor belts that may be of either a perforated or non-perforated material. After traveling the length of the first conveyor, the curd is inverted onto the second conveyor where further matting takes place. At the end of the second conveyor milling or transfer to an external milling device occurs.
Although these systems allow for the continuous drainage of the cheese curd, the curd must be deposited on the conveyor in a layer thin enough to allow the whey to be drained from the curd without agitation. If a layer more than about 3" thick is used with such a system, whey may be trapped in pockets of the cheese curd. This limitation leads to cheese processing systems that are either very large or have a relatively low throughput because of the amount of conveyor belt area required to drain the cheese curd. In addition, such systems are also limited in their production of matted cheese curds.
U.S. Pat. Nos. 4,389,941 describes a continuous system for the manufacture of cheese in which the curds and whey are separated by means of an inclined screen and the curd is further dried by means of peg stirrers as it travels along a first conveyor belt. At the end of the first conveyor belt, the curd is transferred to two consecutive matting or stirring belts before passing through an internal milling device to be salted.
This system may be operated with a much thicker curd layer (8-10") due to the enhanced drainage caused by the use of peg stirrers, thereby decreasing the overall size of the system for a given throughput of product. The use of peg stirrers also allows for the manufacture of several different types of cheese than could be accomplished with the previous systems. Unfortunately, the use of peg stirrers in the early stages of curd drainage tends to shatter the larger curd granules, resulting in an associated loss of bufferfat and moisture. This causes significant difficulties when attempting to manufacture high moisture cheese varieties using such a system.
Although the present systems for the continuous manufacture of cheese are adequate for the production of certain type of cheese varieties, it would be desirable to have a continuous cheese processing system that maximizes the drainage of the whey from the curd while minimizing the amount of mechanical damages to the curd and was also capable of manufacturing both low and high moisture cheese varieties while minimizing the overall size of the cheese processing system.